Maybe the best resource is once you settle on a destination, to put it out there on a new thread, and ask the locals & habituals what they would recommend. Generally, smaller is better. Rural or small town is better. If you have a copy of the Good Sam guide (kind of like a huge Yellow Pages of campgrounds in the US & Canada) you can get a fair bit of information from their RV park descriptions.
Are you OK with boondocking, or do you want full hook-ups? National Park campgrounds usually have on-site water and a sani-dump, typically have some vegetation screening between sites, and you can't beat the scenery.
If you really want more back-of-beyond camping, Colorado is loaded with US Forest Service campgrounds. If you just google the forest of interest, their website should identify their campgrounds (often very primitive, and some are on rough roads, though, so it's best to check ahead.) The Forest Service usually allows dispersed camping unless areas are posted to the contrary.
You are a stone's throw from the red rock canyons of Utah. You can check with BLM field office sites (such as Moab, Price, and Monticello) for their campgrounds and dispersed camping options. We spent a wonderful 5 days in October near the BLM San Rafael Bridge campground in a dispersed campsite in Buckhorn Draw in the North San Rafael Swell. (Price field office, area north of I-70 between Salina and Green River, UT.) Beautiful scenery and very few people. Just bring lots of water, as this is "dry" camping.
These more natural campsites are out there-- despite so many commercial RV parks being just parking lots for tightly-packed big rigs.